u8 len;
u32 modulus;
u32 seed;
+ u32 offset;
};
static void nft_hash_eval(const struct nft_expr *expr,
{
struct nft_hash *priv = nft_expr_priv(expr);
const void *data = ®s->data[priv->sreg];
+ u32 h;
- regs->data[priv->dreg] =
- reciprocal_scale(jhash(data, priv->len, priv->seed),
- priv->modulus);
+ h = reciprocal_scale(jhash(data, priv->len, priv->seed), priv->modulus);
+ regs->data[priv->dreg] = h + priv->offset;
}
static const struct nla_policy nft_hash_policy[NFTA_HASH_MAX + 1] = {
!tb[NFTA_HASH_MODULUS])
return -EINVAL;
+ if (tb[NFTA_HASH_OFFSET])
+ priv->offset = ntohl(nla_get_be32(tb[NFTA_HASH_OFFSET]));
+
priv->sreg = nft_parse_register(tb[NFTA_HASH_SREG]);
priv->dreg = nft_parse_register(tb[NFTA_HASH_DREG]);
if (priv->modulus <= 1)
return -ERANGE;
+ if (priv->offset + priv->modulus - 1 < priv->offset)
+ return -EOVERFLOW;
+
priv->seed = ntohl(nla_get_be32(tb[NFTA_HASH_SEED]));
return nft_validate_register_load(priv->sreg, len) &&
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_HASH_SEED, htonl(priv->seed)))
goto nla_put_failure;
-
+ if (priv->offset != 0)
+ if (nla_put_be32(skb, NFTA_HASH_OFFSET, htonl(priv->offset)))
+ goto nla_put_failure;
return 0;
nla_put_failure: